Info overlay reports 60 UPS but Game Runs Slower

[Adamo]

This is on a multiplayer, modded server. The info overlay reports 60 UPS (or more if I increase game speed to >1), but it's clearly only running at approximately 30 UPS. I can see no difference when I slow down to game speed 0.5, but slower than 0.5 and the game does slow down beyond 0.5 as expected. Anyone seen this behaviour before? Any ideas what to do? It's a big map, and it has been running at low game speeds for a long time. I deleted a bunch of chunks from the map, and now it's able to run better, which caused me to notice this strange behaviour. Thanks!

The speed seems to be fine on singleplayer.

[Zavian]

I suggest you provide the info requested in viewtopic.php?f=7&t=51319

[Adamo]

I suggest you provide the info requested in viewtopic.php?f=7&t=51319

Thanks.

[Zanthra]

With the number of mods you are using, it's possible the texture atlases are too big to keep in the dedicated VRAM of the GPU. Try running the game with VRAM usage set to low or medium in the graphics options and see if that helps.

[Adamo]

With the number of mods you are using, it's possible the texture atlases are too big to keep in the dedicated VRAM of the GPU. Try running the game with VRAM usage set to low or medium in the graphics options and see if that helps.

Thanks for the suggestion. I tried it and it made no difference.

[Klonan]

Is the game running on a server that is lower power than your PC?

It may be that the server is at 30 UPS, but your local side runs the update in less time,
So it reports 60UPS, but is actually limited by the UPS of the server

[Adamo]

Is the game running on a server that is lower power than your PC?

It may be that the server is at 30 UPS, but your local side runs the update in less time,
So it reports 60UPS, but is actually limited by the UPS of the server

It's a good question but I'm confident the server is OK. It's an 8-core enterprise rack server with 32 GB of RAM. I'm not running anything else on it except a few other small clusterio instances and some small background daemons. The resources on the box are still in a high-availability state. However, the possibility exists that the factorio server has maxxed out a single processor and isn't able to use additional resources, I guess. Not sure how that works. I suspect that isn't the issue since I know others who run larger maps without difficulty, and it's unlikely they use a system as powerful as this one.

[Zavian]

Most of the factorio simulation code is single threaded, so maxing out one core is definitely possible.

[Adamo]

Most of the factorio simulation code is single threaded, so maxing out one core is definitely possible.

My single player client is able to run the map fine at 60 UPS. The server is on par with my desktop. Unless the CRC hashing is taking a huge amount of the CPU power, which I suppose is possible.

Since the game seems to be running at exactly half speed, it makes me think that something is not passing the potato. I thought maybe someone may have run into the problem before, but it sounds like maybe not. I can start disabling mods, but it won't be easy to determine the problem, because various parts of the factory will shut down as mods get disabled. It makes dependency-testing very non-linear.

[Loewchen]

There is no doubt that the server is the limiting factor, the only question is why. Post the server log.

[Adamo]

There is no doubt that the server is the limiting factor, the only question is why. Post the server log.

Right.

[Adamo]

Is there a method by which a mod could hold things up at a certain speed? Some functions I could grep for in the code of our mods? Or some way that the game speed can be limited that transcends the game.speed value? It just seems strange that it's perfectly stuck at half speed. We experienced the need to slow down the server because of having a massive base, and have slowed it down to improve smoothness before. This seems different, somehow. Like a sharp cutoff. As I progress through the game.speed values from 0.1 to 1, it abruptly stops increasing after 0.5. In the case where we were experiencing slow downs from having too many chunks in the saved file, the server would try to run faster, but we experienced more and more lag as we increased speed. We do not experience that in this case, just the abrupt failure to increase speed past 0.5.

[Zanthra]

If you start the server on a brand new map with nothing built, do you still have the same speed problems? Are there any other applications on the server that could be using substantial CPU time or memory bandwidth?

[Loewchen]

The E5540 is really weak, it has about half the performance of your 4790K, 30 UPS on a big map is not unexpected.

[Adamo]

The E5540 is really weak, it has about half the performance of your 4790K, 30 UPS on a big map is not unexpected.

I believe you about the processor. The change in character of the reaction still seems suspect to me, though. When the base started to get big, we could see the UPS slowing down on our clients. When we increased speed (just for testing), we would see the UPS increase up to a point. For example, if I set it to game.speed = 1, maybe we'd get to UPS ~47. Of course it would be heavily lagged, with characters blinking around as they tried to walk. When we slowed down the speed to, say, 0.5, then we saw a solid 30 UPS. OK. This behaviour made sense. Now, when I increase the speed to even game.speed = 3.0, the UPS will increase to 180 (no WAY my computer can run it that fast, I would think!), but the speed of the game is still clearly going at ~0.5. No character blinking, just a smooth 0.5. This behaviour seems very different from the one described above.

[Adamo]

If you start the server on a brand new map with nothing built, do you still have the same speed problems? Are there any other applications on the server that could be using substantial CPU time or memory bandwidth?

No. Other multiplayer maps on this server with the same set of mods run very well. As I stated above, only some small daemons and other factorio maps. The server resources are still highly available.

[eradicator]

Is there a method by which a mod could hold things up at a certain speed? Some functions I could grep for in the code of our mods? Or some way that the game speed can be limited that transcends the game.speed value?

There's no normal way for mods to access game speed like that. There's two hacks i can come up, both involving simply not letting you set game.speed higher than 0.5. You can test this by doing

Code: Select all

/c game.speed = 1 game.print(game.speed)

If this doesn't print "1" to the chat, then something is very fishy. If it does print "1" then something else is going on.

[Adamo]

Is there a method by which a mod could hold things up at a certain speed? Some functions I could grep for in the code of our mods? Or some way that the game speed can be limited that transcends the game.speed value?

There's no normal way for mods to access game speed like that. There's two hacks i can come up, both involving simply not letting you set game.speed higher than 0.5. You can test this by doing

Code: Select all

/c game.speed = 1 game.print(game.speed)

If this doesn't print "1" to the chat, then something is very fishy. If it does print "1" then something else is going on.

Thanks, yeah... I did check to see if the game reports back the new game speed after I set it. It does.

[Zanthra]

If you start the server on a brand new map with nothing built, do you still have the same speed problems? Are there any other applications on the server that could be using substantial CPU time or memory bandwidth?

No. Other multiplayer maps on this server with the same set of mods run very well. As I stated above, only some small daemons and other factorio maps. The server resources are still highly available.

If the map with the most entities is the only slow map, I suspect that it is a problem of resource shortage on the server. If you are running multiple factorio instances, while they can divide work among multiple cores, the still share and compete for the same CPU cache and memory interface. I would think it is just coincidental that the server can only reach 30 UPS when you rediscovered the issue. It's possible that the issues causing the bottleneck earlier on was something intermittent, causing the speed on the server to vary from second to second, but as your factory further grew that has now been well overshadowed by more consistent bottlenecks leaving it at a very steady 30 UPS.

[Adamo]

If you start the server on a brand new map with nothing built, do you still have the same speed problems? Are there any other applications on the server that could be using substantial CPU time or memory bandwidth?

No. Other multiplayer maps on this server with the same set of mods run very well. As I stated above, only some small daemons and other factorio maps. The server resources are still highly available.

If the map with the most entities is the only slow map, I suspect that it is a problem of resource shortage on the server. If you are running multiple factorio instances, while they can divide work among multiple cores, the still share and compete for the same CPU cache and memory interface. I would think it is just coincidental that the server can only reach 30 UPS when you rediscovered the issue. It's possible that the issues causing the bottleneck earlier on was something intermittent, causing the speed on the server to vary from second to second, but as your factory further grew that has now been well overshadowed by more consistent bottlenecks leaving it at a very steady 30 UPS.

Perhaps. The main thing that made me think something different is going on is that the UPS numbers report that the game is running faster, but the game does not run faster. With issues in the past, the UPS numbers would level off even if the game speed was increased... Is there a way to confirm the UPS value on the server's end? A console command or something?